Will having a criminal Justice degree suffice?

So I have tried to go into the Police academy this year at two different Dept. I did have one interview at one the other I did not even get to the fitness test. I got a letter from both saying that I was not accepted, but to try again in a year. I got to thinking. They have 60 slots at the one dept to fill, and there was 30 taking the test. I don't have a criminal Justice Degree but am going after it. Would you think that my not being accepted was due in part not being as "prepared" as others since they all almost have a criminal Justice degree? And do you think becoming a security guard while I'm in school would show I can handle security situations? Caring a gun, patrol, report writing that sort of thing?